In Norwalk, the southernmost portion of US 7 is a short expressway. At the northern end of the expressway, US 7 turns east onto Grist Mill Road for a short distance and then north onto Main Avenue. The section of Main Avenue south of this point, which is bypassed by the expressway, is an unsigned state road designated SR 719. It extends south to CT 123 as a four-lane undivided road.